B Allis with an oil leak

[RobbieD]

Hello all! I’m a long time reader but I believe this is my first post, so thanks to everyone for the great info.

Over the last few months, I have managed to revive a 1950 AC model B. However, I have an issue and wanted to see if anyone had any thoughts… Even though the tractor ran when parked and had recently been rebuilt (parked 35 years ago), it had managed to develop a pretty severely stuck engine (cylinders 2 and 3 were pretty bad).

After about a month of trying all the stuck engine tricks (ATF, PB Blaster, Snake oil, etc.), I ended up pulling the head and used a block of wood and hammer to knock the cylinders loose and get them to the bottom. I then cleaned the cylinder walls with a drill and wire brush as best I could, replaced the head gasket/head and torqued, and torqued it again after a couple heat cycles.

I knew I’d have oil consumption, and it smokes a little, and I plan to re-sleeve this winter, but I’m up against parade season and out of time.

The question is sometimes, after about 30 minutes of running, I will have oil coming out the spark plug of cylinder 2 or 3 and once it fouled a plug and went to missing. The plug fouling is completely understandable, and I’m putting in some old school non-foulers on those two cylinders in a bit to hedge a little, but has anyone ever had oil leak out around the spark plugs when it’s not missing? I promise it’s around the plug and not out of the head gasket. And even stranger, it won’t do it all the time.

 

[Jim.ME]

It likely has stuck rings among other things. Driving the piston down and wire brushing the cylinders walls doesn't amount to much. You may have even broken the piston ring lands.

 

[Gary Reif]

This is just a shot in the dark but do those sparkplugs have gaskets on them (copper washers).

 

[RobbieD]

Thank you all for the quick responses.

The plugs have the little seal rings on them, but I don’t think they’re copper. Come to think of it, I haven’t replaced the plugs, only cleaned them up. Are the rings a “one time seal” kinda thing?

Jim, as ugly as I had to be with getting the pistons unstuck, I wouldn’t be a bit surprised to see the damage you described.

 

[Jim.ME]

Thank you all for the quick responses.

The plugs have the little seal rings on them, but I don’t think they’re copper. Come to think of it, I haven’t replaced the plugs, only cleaned them up. Are the rings a “one time seal” kinda thing?

Jim, as ugly as I had to be with getting the pistons unstuck, I wouldn’t be a bit surprised to see the damage you described.

New plugs should have new sealing rings.

 

[Bob Bancroft]

Thank you all for the quick responses.

The plugs have the little seal rings on them, but I don’t think they’re copper. Come to think of it, I haven’t replaced the plugs, only cleaned them up. Are the rings a “one time seal” kinda thing?

Jim, as ugly as I had to be with getting the pistons unstuck, I wouldn’t be a bit surprised to see the damage you described.

No problem reusing spark plugs and the little seal washers on them.
I use the hottest spark plugs I can find in my old gas engines which don't get worked.
I freed up a WD45 once without removing the head. I ran it for a couple of years until one time I worked it hard. Must be the rust and crap burned off the valves because after that I had to pull the head for a valve job!

 

[RobbieD]

Man I hate to hear that. Seems like you’ll always find a weak point somewhere on one you’re trying to bring back to life. There was a sticky valve or two on this guy too when I took the head off, but they didn’t look super bad. I doubt this guy will see much hard work anytime soon, but you never know.

Well, new set of plugs today and a couple new anti-foulers on the cylinders that were hurt. Drove it around the fields and hills for a good 45 minutes and no oil leaks!

I’ll admit I may not have been tightening the old plugs enough. I saw on the new package that they recommend a half turn after finger tight. That seemed like too much on these old threads, but I did go a heavy quarter turn (everything seems to have aluminum heads these days and the spark plug threads scare me to death).

Thanks again for the help guys. I’ll try to attach a picture as I right proud of how this little guy has turned out. Kinda makes me want to find another one and go after it…

 

[mdm1]

Yup that's how it starts!